Crystal Clear Aquatics zaptasia control gel is a unique all natural, non-toxic solution to aiptasia growth in marine aquariums. The slow dissolving formula allows the components to grip the anemone, ensuring complete control of regrowth. Zap-tasia control gel is fish and reef safe. Any excess gel will dissolve over a short time and is harmless to tank and inhabitants. Any localized pH decrease dissipates quickly and is harmless to any tank inhabitants. Zap-tasia control gel can also be used to combat other nuisance anemones and polyps. Comes with 2-piece per pack.